Drug interactions
Amitriptyline + Nelfinavir
Severity: Moderate
Amitriptyline and Nelfinavir: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Nelfinavir inhibits CYP3A4, which contributes to amitriptyline metabolism, so tricyclic concentrations may rise. This can increase anticholinergic effects, sedation, and cardiac conduction effects including QT prolongation.
What this interaction means in plain words
Amitriptyline and Nelfinavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Amitriptyline belongs to Central Nervous System; Nelfinavir belongs to Anti Virals.
Why it happens
Inhibition of CYP3A4-mediated demethylation of amitriptyline by nelfinavir.
What to do
Start with a low amitriptyline dose and titrate to response, monitoring for anticholinergic toxicity. Consider ECG monitoring in patients at cardiac risk or on higher doses.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Other interactions of Nelfinavir
- Alfuzosin + Nelfinavir Contraindicated
- Avanafil + Nelfinavir Contraindicated
- Dronedarone + Nelfinavir Contraindicated
- Eletriptan + Nelfinavir Contraindicated
- Ergotamine + Nelfinavir Contraindicated
- Flibanserin + Nelfinavir Contraindicated
Frequently asked questions
Can I take Amitriptyline with Nelfinavir?
MediHelp rates the interaction as moderate. Amitriptyline and Nelfinavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Nelfinavir inhibits CYP3A4, which contributes to amitriptyline metabolism, so tricyclic concentrations may rise. This can increase anticholinergic effects, sedation, and cardiac conduction effects including QT prolongation.
How serious is the interaction between Amitriptyline and Nelfinavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with a low amitriptyline dose and titrate to response, monitoring for anticholinergic toxicity. Consider ECG monitoring in patients at cardiac risk or on higher doses.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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